If it were a Capitol Hill popularity contest, Rep. Howard Berman would likely be headed for a runaway victory. But the 15-term lawmaker, who’s never won with less than 60 percent of the vote, is facing significant geographic and demographic disadvantages in California’s San Fernando Valley against fellow Democratic Rep. Brad Sherman.

The question hanging over the high-profile race is how Berman, the overwhelming favorite among the California delegation and Hollywood royalty, picks up ground in a redrawn district that includes far more of Sherman’s current territory.

When the two colleagues face off in the 30th district general election, potentially more than two times as many voters will participate than voted in the low turnout, seven-candidate all-party primary on June 5. The two Democrats, drawn together by redistricting, combined to receive 75 percent of the vote, with Sherman outperforming Berman by 10 points.

“It’s just a brand new electorate,” Berman campaign manager Brandon Hall said, “and an electorate that we feel is much more favorable to us.”

An independent statistical analysis of the primary, set to be released today by Democratic consulting firm Redistricting Partners, found that Sherman performed decisively better than Berman among “decline to state” party preference voters and in areas with significant Latino populations, which are largely in Sherman’s current district. “Those are the growth markets in the general election,” the firm’s founder, Paul Mitchell, said by phone on Tuesday.

The analysis is not a general election predictor, but it provides a detailed illustration of where Sherman and Berman, who won the Jewish vote decisively, performed best in the primary — and where they should focus their efforts going forward.

Among the portions of the three old districts that constitute the new 30th, Sherman won the part of the redrawn district that he currently represents — which accounted for nearly half the total vote — 49 percent to 25 percent, and the area carved out of Rep. Henry Waxman’s (D) district 41 percent to 29 percent. Berman won his current territory 49 percent to 32 percent.

“All along the race has been about geography,” Sherman consultant Parke Skelton said. “Who represents what is an overwhelming factor. Not who does Betty White support.”

The television star endorsed Berman and made a cameo in one of the Congressman’s pre-primary ads. Berman spent about $1 million on cable TV in the prohibitively expensive Los Angeles media market, and a pro-Berman super PAC spent another $500,000 — combining to spend three times what Sherman did on TV — all highlighting Berman’s endorsements and work for the district.

But don’t expect Berman’s messaging to stay purely positive in the general. The campaign plans to hammer home what differentiates the two Democrats who don’t seem all that dissimilar.

Hall said the campaign would also be more vigilant in defending Berman’s record against attacks by the Sherman campaign, which distributed about twice as much direct mail as Berman during the primary.

“In Brad Sherman’s 16 years in Congress, he’s passed a total of three bills, and two of those are naming post offices,” Hall said. “That’s a line you’ll hear often between now and November because it really draws a contrast between these two Members of Congress, what they’ve accomplished and their effectiveness for the district.”

When asked for comment in the Capitol last week, two of Berman’s backers in the delegation — Waxman and Rep. George Miller — were unconcerned about his prospects.

“I think he’s got to let people know how effective he is and how highly regarded he is by his colleagues,” Waxman said. “The other thing is he’s got to talk about what he’s done for them, because while he’s a national and international figure, he’s done a lot for the San Fernando Valley, and people have got to know about it.”

The home page of Berman’s campaign website features testimonials from endorsers such as Sen. Dianne Feinstein (D-Calif.), actress Morgan Fairchild and California Gov. Jerry Brown (D), who says Berman “knows what the hell he is doing and he can work with the other side.”

According to a Sherman campaign analysis of the primary, 35 percent of primary voters were Republican, yet only 22 percent of the vote went to the three GOP candidates. Skelton said that means more than a third of Republicans have already chosen which Democrat they support. The Redistricting Partners analysis found that Sherman won the second most GOP votes, even with three Republicans on the ballot.

While there will certainly be some outreach to Republicans, Skelton said, most of the new voters in November will be Democrats and “decline to state” voters, and the electorate will be younger and have a higher percentage of minorities — voters coming out to support President Barack Obama. He believes the percentage of the vote from Sherman’s current territory will also increase, giving Sherman an added advantage.

The second-quarter fundraising deadline is Saturday. Sherman went into the final weeks of the primary with $3 million in cash on hand after spending $1.2 million from April 1 to May 16 and $2.2 million for the entire cycle. Berman spent $1.8 million during that span — and more than $3.5 million overall — leaving him with $821,000 in mid-May.

“I think Berman is trying to figure out how to raise the money to be competitive right now,” Skelton said. “We’re just building up infrastructure to reach a broader electorate right now.”

Hall said Berman was able to spend more in the primary because of his stellar fundraising ability. Not counting interest from investments of campaign cash, which Sherman deftly benefited from, Berman has raised more than twice as much as Sherman in 2012. Since November 2010, not counting $950,000 in interest and a personal loan, Sherman has raised about $1.2 million to Berman’s $3.1 million.

“They saved their money because they had to,” Hall said. “Our ability to reload for the general — we’ve always been confident in that. So we were OK spending down, because we knew we could still continue to raise. Brad Sherman had to conserve his money because he can’t raise money.”